Its a bit difficult to explain. His company he was working for was partnered with Microsoft at first for the release of D4 then it was released to PC not being part of Microsoft but then Swery ended up becoming very sick to the point where his white bloodcell count was very very low putting him out of work for a long while which caused him to miss deadlines and have issues with the company he was currently with. He went on to get help with it and also went on a spirtual journey after doing so and became a monk after all of this he decided to leave the company to continue his training as a monk but due to the way he left so suddenly it caused both bad blood and a falling out and the company kept all of his work and IPs for themselves. Fast foward about a year later and he decides to make his own company to persue his continued passion of gaming then about a month ago this leak happened before leading up to this fig croudfunding campaign that just failed.
So the simple answer is, he doesn't even have the RIGHTS to make D4, because he doesn't own the IP anymore. That's not terribly complex
I've been playing this game a lot lately I think I'm at 70+ hours now and still loving it and I'd love a Loki Key.